WIP: add option to get OAuth URL based on grant type
WIP: add option to get OAuth URL based on grant type

sphereio/sphere-php-sdk,sphereio/commercetools-php-sdk,sphereio/commercetools-php-sdk,sphereio/sphere-php-sdk,sphereio/commercetools-php-sdk,sphereio/commercetools-php-sdk,sphereio/sphere-php-sdk,sphereio/sphere-php-sdk